import React, { useState } from 'react'
import Count from './Count'

export default function App() {
  const [bBar, setBBar] = useState(true)
  return (
    <div>
      <h2>App</h2>
      <button onClick={() => setBBar(!bBar)}>创建/销毁</button>
      {bBar ? <Count /> : null}
    </div>
  )
}
